02 2500 tranny issues

Have an 02 chevy 2500hd with the 6.0 gas motor. Sometimes it is fine other times it doesnt run right. Seems to happen more when it is warmed up. If I stomp on the gas nothing happens, the motor just starts to cut out, torque converter doesnt slip or anything.When I first start it, it runs great but then it will get to where it takes for every to get up to speed because the tranny wont do anything. Was told to change the tranny filter, so will change all my filters tonight. New to chevys and only had this for a week. Any help will be super helpful!